Loading system for blast-furnace

ABSTRACT

A loading system for a blast-furnace having a very high counterpressure, characterized by a rotary distributor, a throat member and a ring member mounted between the said distributor and throat member, the said ring member being gas sealed at high pressure and temperature, the said distributor comprises a conical spout adapted to rotate with the ring member, a weir pipe connected to said spout at an angle of approximately 40* to 50* from the vertical, a liquid tubing located along the axis of rotation of the said distribuotr and ring member, the said tubing adapted to receive a cooled liquid for cooling the spout, the said spout being adapted to spread materials such as coke, sintered ores, and various additions inside a blast-furnace to give the said materials an M profile.

Pmmcnmasm 3799.368

sum 2 or a PAIENIEB R26 I974 saw u am FIGS LOADING SYSTEM FORBLAST-FURNACE This invention relates to the loading system of ablastfurnace operated at a very high counter-pressure, according tosystems in M, 2M and 3 M, that is to say, that a vertical section of ablast-furnace shows the loading line of the materials to the throat as1M, 2M or 3M. Loading in M has been known for a long time byblastfurnace specialists, but loading in 2M or 3M is new to them. Thesame system is used for the three types of loading, and a very highcounterpressure of more than 2 bars, or 30 psi is obtained by means oftwo valves connected in series with a rotary extractor for the materialenclosed in a bin, which can resist very high pressure. The lay-out ofthe essential elements and the functioning principle of this systemprevents the wear between contacting surfaces of the extractor and ofthe seats of the valves.

The main idea of this invention is to use 2 or 4 or 6 bins, according tothe desired loading, i.e., a loading in M, 2M or 3M. While 1, 2 or 3bins are loaded with materials by conveyors or skip-cars, 1, 2 or 3other bins unload their contents in the throat by means of a turningspout which is located in the axis and at the top of the metal shell ofthe blastfurnace.

Systems in M, 2M or 3M allow for an almost unceasing loading of theminerals, coke, various additions and sinter pellets in a given orderand in carefully proportioned quantities without any alteration in thecounterpressure of the blast-furnace which remains nearly constant andvery high, contrary to standard blast-furnaces in which, during anyloading, there is a very important falling of pressure.

If the standard system of loading with bells and cones is satisfactoryfor useful volumes up to 2,500 m and a counter-pressure up to 1,5 bar,for a 4,000 m volume with a counter-pressure exceeding 2 bar, sizes andweights of the elements of the loading system become huge and verydifficult to work out. The resistance to abrasion and the tightness ofthe system imply very frequent overhauls and partial stoppages with theconsequence of very big production losses. For a quick overhaul ofsystems up to 150 tons, some builders, at a level higher than 80 meterslay out a bridge crane of almost 400 tons weight, and it implies thebuilding of giant square towers.

The system of loading in M, 2M or 3M has the great advantage of beingsimple, comparatively light, easy to assemble, to keep and to repairbecause the heaviest element weighs less than tons. The possibility ofworking with half of the equipment, without any stoppage of theblast-furnace, with only a temporary slowing down, during the repair ofthe defective elements is one of the main qualities of theseconstructions.

The main advantages sought for during the research for these loadingsystems in M, 2M or 3M were obtained as follows:

1. The very high counter-pressure and the lasting tightness was obtainedfrom the upper two-way duct, by using in series, a seat valve controlledwith a lower tightness seat which never touches the very abrasivematerials such as coke and sintered pellets, this valve standing on abin which can resist very high pressure and temperature, with in thelower part a rotary extractor with pellets in a barrel, also avoidingthe abrasion of the walls by its direction of rotation. Then stands asecond seat valve, built in a similar way to the upper valve. It is heldby means of a sleeve to the hood of a rotary distributor, which has theshape of a cone going into the throat of the blast-furnace and by meansof a single, double or triple pipe, unloads materials into theblast-furnace, while rotating at a speed of 15 to 30 revolutions perminute. The part which stands in the blastfurnace under a gastemperature of 400 to 500 C must be cooled by water circulation in awater-jacket. The inlet of water and its outlet is aligned with therotation axle by means of a particular bearing. The throat of thedistribution is held in a tight ring, with a bearing having crossrollers, the said bearing has to support a dissymetrical load. Thisring, strongly and precisely built, must also avoid any leakage of hotgas from the blastfurnace. The rotation of the funnel distributor ismade by a reducer and an electric motor.

2. The reduction of weights and sizes of the equipments, the economy onelectric energy, are obtained by means of a working cycle which isalmost continuous, based on the reciprocating functioning of 2 identicalassemblies of the system which work in relays to carry out at the sametime, either the filling up of the bin or the loading of theblast-furnace. So, when the upper valve opens, the two-way duct guidesmaterials to one of the bins, the extractor of which has stopped, theother bin is under pressure, with its upper valve shut, its lower valveopens and the extractor is working. When a bin is loaded, the other oneis unloaded and vice versa. The following stages go on uninterrupted.The times of the different operations depend on the characteristicsrequired for a blast-furance and on the size of equipments.

a. When the storage bin is empty and under high pressure, the uppervalve being shut, the rotary extractor stops, the lower valve shuts. Thebin is put under decompression by evacuation of gas. When the bin is atatmospheric pressure, the upper valve opens. Into the storage bin whichstands between the gas uptakes the upper two-way duct or a skip car,pours a load of materials which is carefully prepared and in aproportioned quantity.

b. When the storage bin is full*of ore, coke, sintered pellets or otheradditions of the load, the upper two-way duct rotates to stop thefilling up, the upper valve shuts, the bin is put under pressure by theinlet of gas from the first dust separator, the pressure of which isalmost similar to that of the throat and the temperature of which isslightly lower. The vaporization of humidity of materials charged canraise the pressure a little but does not interfere with the followingoperations, on the contrary.

c. When the bin pressure is in balance or superior to the pressure inthe throat of the blast-furnace, the lower valve opens by swinging outof the way of the fall of materials. The extractor is set to work andpours portions of materials in the duct related to the distributor. Thepath followed by the abrasive materials avoids as much as possible theabrasion of the extractors body during its rotation. The materials arelifted up during the taking away in the storage bin and fall into theturning spout without wearing out the extractor. Removable and very hardplates are nevertheless provided, such as to avoid, as much as possibleabrasion and to be replaced easily, in a hurry, and without stoppage ofthe working blast-furnace. The pipe of the pipes of the rotarydistributor pour out materials onto circles inside the blast-furnace.The material falling on top of the stack shows a section in M, or in 2Mor in 3M.

d. As soon as the bin is empty, the lower valve shuts after theextractor has stopped. The different operations previously explainedbegin another cycle as in a).

3. When one assembly of the system is at stage a), the other assembly isat stage c) so that the rotary distributor is almost all the time loadedwith materials and turns without any interruption. The loading level canbe determined outside the circle swept by the biggest pipe or by anyother means as TV camera for infra-red, echo-sound, radiationmeasurement level. The time wasted is limited to compression ordecompression periods of the materials storage bins.

4. If the loading system in M is made with the present equipments ofblast-furnace, the loadings in 2M and in 3M are only possible when usinga rotary distributor with separated conical shapes, each with its outletpipe. If there are two concentric separated conical bins there is a needfor four storage bins and two outlet pipes. If there are six sets ofstorage bins, there are three concentric conical bins and three outletpipes for discharge of materials inside the blast-furnace. A greaternumber will not be needed because the possibilities of diversifying thematerials loads are numerous enough with the 3M system.

5. It is comparatively easy, in a short time, to shift from a loadingsystem in 3M to a system in 2M. One needs only to stop 2 sets of bins.In the same way, one can shift from a loading in 2M to a loading in M.One can come back to a loading system in 3M from a loading system in 2M.In the same way, the transfer may be from a loading in M to a loading in2M.

6. During a short slowing down, it is possible to add two sets of binsand to shift from a system in M to a system in 2M, from a system in 2Mto a system in 3M. The longest modification is the exchange of therotary distributor which, it seems, can be done during a very shortstoppage of the blast-furnace, these transformations must be foreseenduring construction by setting of a sealing ring for a greater rollerbearing. This possibility is a security which can lead to a better useof the blastfurnaces, regarding the available materials and thepercentage of ore and sintered pellets, the quality of coke and alsoregarding the enrichment of the hot blast with oxygen.

7. The time of the working cycles for each set can be modified andregulated, according to technological needs, from the results of variousoptimization and development experiments, not only about the loadingparts of the furnace, which are comparatively easy to modify but alsoabout the various other equipments such as cowpers, cooling ofblast-furnace shell, the cast house, the shell, the refractories, theturbo-blowers and also the dust-catchers.

8. The number of combinations for the various loadings is nearlyinfinite and that is why a high automation level with the use of anindustrial process computor would allow the printing of a very precisechecking diary about the many parameters and effective programming ofthe blast-furnace loading, on which particularly depends the pig ironproduction.

9. The loading system in 3M has for its main purpose, the making, in thecenter of the blast-furnace, of a column of materials which couldincrease the heat energy and the reduction gas for process, could raisethe inside temperature, especially in the stack and bosh axes, far fromthe refractory walls and from the cooling of the blast-furnace shell. Tospare the very expensive coke, the use of prepared coal or anthracitedirectly inside the central column would reduce the coke consumption.The central column would be divided by thin layers of other additionsfor instance flux or limestone, or pellets.

10. The booking of loads, which are very common in classical furnaceswill be almost eliminated by loading in 2M or in 3M, because the contactsurfaces between outer and inner layers of materials facilitate slidingsand relative movements of the different blocks of load, specially in thestack, the slower ones being along the walls, as protection andlubricant, the faster ones in the center.

1 l. The counter-pressure in the throat can easily be increased becausethe tightness of the valves is excellent and lasting during years. Onemust rather try to improve the development of the other elements of theblast-furnace to go into higher pressures.

12. The loading system being lightened, it will again be possible toavoid the construction of gigantic square superstructures and to have onthe shell the possibility to carry the whole loading equipments. The gasuptakes could be used as carrying pillars for the storage bins and otherelements of the loading systems in M, in 2M or in 3M.

An historical account of the evolution in blastfurnace is also therecord of a slow progress up to 1950, followed by a quick evolutionsince then, the increase in the productivity of blast-furnaces beingmarked by stages which always are inventions such as the shell,skip-cars, MacKee bells, fuel oil injection, cooling of the hearth, etc.But unfortunately there is a tendency now to increase excessively thedimensions of standard equipments which have stood the test of timerather than looking for new solutions. The system in M, 2M and 3M may bea solution for the very numerous problems which results from thenecessity of technical progress in the construction of blast-furnaces.

The characteristics and the advantages of the systems in M, 2M and 3M ofthe loading of a blast-furnace with a very high counter-pressure resultfrom the descriptions which follow, as examples referring to theenclosed drawings in which:

FIGS. 1, 2 and 3 cross-sections views of a blastfurnace respectivelyhaving a loading in M, 2M and 3M.

FIG. 4 is an enlarged section of a blast-furnace having a loading in 3M.

FIG. 5 is a schematic view of a construction according to the invention.

FIGS. 6, 7 or 8 respectively show loading assemblies in M, 2M and 3M,and

FIGS. 9 and 10 are sectional views of equipments for the loading in 2Mand 3M.

FIG. 1 is a cross-section of a schematic profile and the loading in M ofa blast-furnace in which 1 is the blast area of combustion, 2 the slagvolume, 3 liquid pig iron, 4 a layer of coke, 5 a layer of sinteredpellets, 6 various additions such as limestorne, manganese or iron ores.This loading section in M is also called loading as ring byblast-fumaces specialists (in FRANCE). This term -M- seems better for anidea as the one described, because these letter pictures the loadingline in the blast-furnace better.

FIG. 2 is also a diagrammatic section, representing a load in 2M in ablast-furnace. The 1 to 6 reference marks are as in FIG. 1 and theremarks are the same, but there is a clear distinction of the separationline between inner and outer loads, a conical shaped surface which makesthe hooking more unusual and easier the slidings of materials to beturned into pig iron.

FIG. 3 is a third diagrammatic section showing the section or 3M profileof the loading level in a blastfurnace. The 1 to 6 reference marks arethe same as in FIG. 1 and remarks about FIG. 1 and 2 can be taken intoaccount also for FIG. 3. A distinctive feature is represented by 7showing a column of prepared materials: these could be coke but alsocoal or anthracite. The purpose of this mass is to increase the quantityof reducing gases highly, to reduce the coke consumption by use of coaland to raise the temperature level in the axis of the blast-furnace,very far from the refractory layer. This version of loading in 3M shouldfind an application in blast-furnaces of more than 4,000 m of usefulvolume, in which the inner diameter of the hearth exceeds 14 meters.

FIG. 4 is an enlarged section of the loading profile in a blast-furnaceas 3M, with reference 4 representing coke, 5 sinter pellets and 6various additions. The laying out of the layers of materials which godown into the stack of a blast-furnace is represented from hypothesiseswhich are still very difficult to check. If the phenomenons which takeplace now in the blastfurnace are not entirely explained, the idea whichis the aim of the invention, is a very important anticipationcharacterized by FIG. 4. There are numerous possible combinations forloading with system 3M, and this system opens a new path for the pigiron metallurgy.

. FIG. 5 represents a construction drawing which is rather schematizedbecause the loading system in M is the basis for system 2M and system3M. This section shows in 5 a sinter pellets layer, in 6 variousadditions. The materials to be loaded are brought by a conveyor 8, fallin the two ways duct 9, which guides them into the storage-bin 12, theswing-valve 10 being open and the tightness surfaces not subjected towear. The rotary extractor 14 is stopped and the lower swing-valve l6shut and very light, bearing its seat by very high counter-pressure inthe throat of the blast-furnace. Storagebin 12 is in the loading stage,the upper swing-valve 11 is shut and bears upon its seat by means of thecounterpressure in storage-bin 13 in unloading stage in theblast-furnace. The rotary extractor turns unclockwise, and it reduces toa minimum the wear of the carter. Swingvale 17 is open and the materialsfall into the spout of the rotary distributor 18 which turns with aspeed of X 30 r.p.m. and facilitate a regular distribution of the load,by means of a single weir pipe 19, cooled by water circulation in awater-jacket. The rotary distributor bears upon a gas tight ring whichis rigidly locked to the throat 22, with an incorporated roller bearing.In is represented a motor element and 21 is a special bearing whichallows for inlet and outlet of cooling water for the weir pipe 19,working under a surrounding temperature of 400 to 500 C. Theblastfurnace gases go out by the gas uptake pipes 23 which are also usedas construction pillars for hoppers 12 and 13. As these must resist veryhigh pressure and temperature, the shape of two half-cylinders having acommon middle wall seems the best solution. The putting in pressure ofhopper 13 is done by the use of the threeway valve 24 and thedecompression of gases in hopper 12 is done by the three-way valve 25.The four-way valve 26 does the same work for rotary extractors 14 and15. The chronological order of work and the dephasing is explained infull details in page 3, a, b, c, and d FIG. 6 shows a diagram of theloading system in M, with the materials conveyor in 8, or a skip-car, 9is a two-way weir feeder, l0 and 11 the upper tightness swing-valves,one being open when the other is shut, 12 and 13 two hoppers, one beingloaded when the other is unloading into the blast-furnace, l4 and 15 therotary extractors, one being stopped when the other is functioning, 16and 17 the lower tightness swingvalves, the first shut when the secondis open. The rotary distributor 18 with its single weir pipe 19 unloadsmaterials into the throat 22 of the blast-furnace. So when a set ofelements 10, 12, l4, 16 is at the stage of loading materials into thehopper, the other set of elements 11, 13, 15 and 17 is loading theblast-furnace.

FIG. 7 represents a diagram of the loading system in 2M with the samereferences as previously in FIG. 6, with the same symbols and remarksfor its functioning; the staggered parallel system of the 2 groups of 2assemblies can be varied, according to the need of the blast-furnacejob.

FIG. 8 diagram represents the loading system as 3M with the samereferences and the same symbols as in FIG. 6. This schematic view isaimed at showing the engineering of 2M and 3M systems from the 1Msystem,

in a better way.

FIG. 9 is a section view of loading system equipments for 2M, in whichthe double rotary distributor 27 is mainly shown because all the otherelements drawn in FIG. 5 would only have added confusion to theunderstanding of the whole, if they had been shown. Then to understandfully the system 2M, one must by looking at FIG. 5 and at FIG. 7, andcomplete the FIG. 9 by drawing the four hoppers and other elements, oreven better build a small model, with two weir pipes.

FIG. 10 shows a vertical section view of the lower equipments in loadingsystem 3M, with 28 as a triple rotary distributor and three weir pipes.The arrows show the outflow of materials, and one of the circuits standsat stage compression-decompression of the 2 sets of materials hoppers.The preceding remarks for FIG. 9 also applies to FIG. 10.

I claim:

1. A blast-furnace and loading system therefor comprising:

a. a blast-furnace having upright walls and an upper throat area;

b. a loading system including a rotary distributor having a plurality ofweir pipes extending into said 'throat area;

c. each of said weir pipes having a discharge opening, said dischargeopenings being disposed in radially staggered relationship relative toeach other, the radially outermost discharge opening being spacedradially inwardly from said furnace walls a substantial distance;

. whereby said loading system may spread a plurality of differentmaterials and may give to the materials in the blast-furnace a profilehaving a cross-section with a plural M configuration.

2. A system as recited in claim 1, wherein the radially innermostdischarge opening is spaced a substantial distance from the axis ofrotation of the rotary distributor to further facilitate formation of amaterial profile in the blast furnace having a cross-section with aplural M configuration.

3. A system as recited in claim 1 wherein:

a. said rotary distributor includes a plurality of concentricallydisposed spouts, each spout communicating with one of said weir pipes;

b. a pair of inlets communicating with each of said spouts and meansassociated with each inlet for closing one inlet when the other is open,whereby, through alternate use of said inlets, material may besubstantially continuously fed into the blastfurnace without loss ofpressure.

4. A system as recited in claim 1 wherein said weir pipes are disposedin side-by-side, staggered parallel relationship.

5. A loading system for a blast-furnace comprising:

a. two rotary distributors;

b. two weir pipes, each communicating with one of said rotarydistributors, said weir pipes being disposed in staggered parallelrelationship;

c. two sets, each of which includes a pair of material hopperscommunicating with said rotary distributor and a pair of valve means,each valve means being disposed between one of said hoppers and saidrotary distributor;

d. one valve means of each pair blocking communication between one ofsaid hoppers of said pair and one rotary distributor while the othervalve of said pair is open, whereby one hopper may be filled while theother is discharged, whereby alternate filling and discharge of saidpair of hoppers of each set effects a substantially continuous feedingof material into the blast furnace without loss of pressure.

6. A loading system as recited in claim 5 including three of said sets,three rotary distributors and three weir pipes, each weir pipecommunicating with one of said rotary distributors, said weir pipesbeing disposed in a staggered parallel relationship.

7. A loading system as recited in claim 6, wherein said rotarydistributors and weir pipes are adapted to spread materials inside ablast-furnace to give a M profile, said system further comprising meansfor alternatively modifying the system from a M profile, to 2M profileand 3M profile.

8. A loading system as recited in claim 5, wherein said pair f hoppersof at least one set each have a halfcylindrical cross-section with acommon median wall.

9. A loading system as defined in claim 5 wherein each of said setsfurther comprises:

a. a feeding duct communicating with both hoppers of said pair;

b. a pair of upper-swing valves, each swing valve being associated withone of said hoppers of said pair for opening and closing communicationbetween said feeding duct and said pair of hoppers of each set;

c. a pair of rotary extractors each of which is disposed between onehopper of said pair and one rotary distributor for controlling the flowof material from each hopper of said pair when its associated valvemeans is open.

1. A blast-furnace and loading system therefor comprising: a. ablast-furnace having upright walls and an upper throat area; b. aloading system including a rotary distributor having a plurality of weirpipes extending into said throat area; c. each of said weir pipes havinga discharge opening, said discharge openings being disposed in radiallystaggered relationship relative to each other, the radially outermostdischarge opening being spaced radially inwardly from said furnace wallsa substantial distance; d. whereby said loading system may spread aplurality of different materials and may give to the materials in theblastfurnace a profile having a cross-section with a plural Mconfiguration.
 2. A system as recited in claim 1, wherein the radiallyinnermost discharge opening is spaced a substantial distance from theaxis of rotation of the rotary distributor to further facilitateformation of a material profile in the blast furnace having across-section with a plural M configuration.
 3. A system as recited inclaim 1 wherein: a. said rotary distributor includes a plurality ofconcentrically disposed spouts, each spout communicating with one ofsaid weir pipes; b. a pair of inlets communicating with each of saidspouts and means associated with each inlet for closing one inlet whenthe other is open, whereby, through alternate use of said inlets,material may be substantially continuously fed into the blast-furnacewithout loss of pressure.
 4. A system as recited in claim 1 wherein saidweir pipes are disposed in side-by-side, staggered parallelrelationship.
 5. A loading system for a blast-furnace comprising: a. tworotary distributors; b. two weir pipes, each communicating with one ofsaid rotary distributors, said weir pipes being disposed in staggeredparallel relationship; c. two sets, each of which includes a pair ofmaterial hoppers communicating with said rotary distributor and a pairof valve means, each valve means being disposed between one of saidhoppers and said rotary distributor; d. one valve means of each pairblocking communication between one of said hoppers of said pair and onerotary distributor while the other valve of said pair is open, wherebyone hopper may be filled while the other is discharged, wherebyalternate filling and discharge of said pair of hoppers of each seteffects a substantially continuous feeding of material into the blastfurnace without loss of pressure.
 6. A loading system as recited inclaim 5 including three of said sets, three rotary distributors andthree weir pipes, each weir pipe comMunicating with one of said rotarydistributors, said weir pipes being disposed in a staggered parallelrelationship.
 7. A loading system as recited in claim 6, wherein saidrotary distributors and weir pipes are adapted to spread materialsinside a blast-furnace to give a M profile, said system furthercomprising means for alternatively modifying the system from a Mprofile, to 2M profile and 3M profile.
 8. A loading system as recited inclaim 5, wherein said pair of hoppers of at least one set each have ahalf-cylindrical cross-section with a common median wall.
 9. A loadingsystem as defined in claim 5 wherein each of said sets furthercomprises: a. a feeding duct communicating with both hoppers of saidpair; b. a pair of upper-swing valves, each swing valve being associatedwith one of said hoppers of said pair for opening and closingcommunication between said feeding duct and said pair of hoppers of eachset; c. a pair of rotary extractors each of which is disposed betweenone hopper of said pair and one rotary distributor for controlling theflow of material from each hopper of said pair when its associated valvemeans is open.